Refined the submit algorithm with more owner fixes, plus a final cache update
Handled a case in which a user by moving the generated room would keep the moved user as the owner of the room, resulting in the user to be in two rooms at the same time
[+] Added the Drag'n'Drop mechanism in the wizard page, allowing to move orders between rooms, plus a 'placeholder' space to temporarily keep orders to move others
[minor fix] Item category maps might be filled twice with the same IDs
Andrea